Spinal stabilization system

ABSTRACT

The present invention is directed to a spinal implant system that incorporates unique snap, or spring loaded, features to assist the surgeon in the placement of screws, rods, hooks and transverse connectors. The poly-axial movement also uses a more direct loading lower saddle into the bone screw to improve locking of the construct.

CROSS-REFERENCE TO OTHER APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/198,447 entitled “Spinal Stabilization System,”filed Mar. 5, 2014, and further claims the benefit of U.S. ProvisionalPatent Application Ser. No. 61/875,239 entitled “Spinal StabilizationSystem,” filed Sep. 9, 2013, the disclosures of which are bothincorporated herein by reference in their entireties.

TECHNICAL FIELD

The present invention relates to devices and methods for assembling andadjusting orthopedic constructs connected to bony anatomy of a patient.More particularly, the present invention relates to improved devices andmethods for pedicle screw and rod-based fixation assembly systems thatutilize monoaxial and/or polyaxial bone screws, such as spinal fixationsystems and associated components.

BACKGROUND OF THE INVENTION

A wide variety of surgical techniques and associated instrumentationsystems have been developed for correcting degenerative disc disease,spondylolisthesis, spinal deformities, or other spinal conditionsthrough minimally invasive or invasive spinal surgery. Spinal correctionduring surgery may be performed by a variety of methodologies that mayfrequently require stabilizing a portion of the spine to allow bone orother tissue growth between vertebral bodies such that a portion of thespine is stabilized into a solitary unit and/or specified shape.

Numerous surgical instrumentation systems have been developed andcommercialized for stabilizing and correcting spinal conditions and/ordeformities. In one of the most popular types of spinal stabilizationsystems, pedicle screw and rods systems, two or more screw assembliesare secured into bony structures of the a patient's vertebrae, and a rodor other device is connected between the screw assemblies, typicallydisposed longitudinally along the length of the spinal segment to anchorthe two or more vertebral bodies relative to each other. The rod can bearranged in a variety of positions and/or configurations (including theuse of multiple rods and/or cross-bars, where desired) according to thepatient's anatomy and/or the correction desired. In many cases, thepatient's anatomy and/or the desired surgical correction required canrequire aligning one or more rods and associated pedicle screws atvarious multi-axial angles and/or orientations along the length of theportion of the spinal segment.

Unfortunately, existing pedicle screw systems are typically rather largeand bulky, and the modularity and/or flexibility designed into thecomponents in many of these systems can render the systems difficult fora surgeon to use effectively. For example, the various feature thatfacilitate the assembly of different size and/or shape rod and screwconstructs, and eventual “locking” of the components together (i.e., thepedicle screw assembly and the rod) to specified orientations, shapesand/or multi-axial angles (prior to fixation) can be difficult and/orimpossible to assemble within a wound. Moreover, where components havebeen preassembled, such as where a pedicle screw subassembly includes atulip head pre-connected with a mono-axially and/or poly-axiallyadjustable bone screw shank, the tulip head will desirably move relativeto the shank. In many such instances, however, manufacturing and/orassembly of the tulip head, relevant inserts and/or the shank itself canresult in a subassembly where the shank/head is loose and can “flop”around, making it extremely difficult for the surgeon to assemble theconstruct and/or tighten the remaining components together.Alternatively, the tulip head may be too tight relative to the shank,rending it difficult and/or impossible for the surgeon to adjust theassembly by hand (prior to fixation).

Assembly difficulties can also be experienced when positioning and/orconnecting one or more of the rods to the implanted pedicle screws.Because patient anatomy is unique, which can often be compounded bysignificant preoperative deformity, rarely do the implanted pediclescrew heads conveniently “line up” in a uniform manner. In fact,implanted screws can often be significantly displaced from adjacentscrews. Also, when the surgeon places a rod into pedicle screws, the rodmay slide to an undesired position or otherwise be displaced or movedbefore the surgeon is ready for tightening the remaining componentstogether. This may inconvenience the surgeon and might require surgicalassistants, technicians or staff members to properly orient the pediclescrew assembly and maintain the rod position while the surgeon fullytightens all of the components together. In many cases, the properfixation of the stabilization system particularly depends on the surgeonand/or staff to properly assemble the rod and the pedicle system, orientthe pedicle screw system, and/or position the rod properly toeffectively lock the components together with the set screw, otherwiseno amount of tightening the set screw will fully or effectively lock thepedicle screw assembly together—i.e., the floppiness remains and the rodmay move axially to an undesired position.

SUMMARY OF THE INVENTION

One aspect of the present invention includes a recognition of a need forspinal stabilization systems that can be partially and/or fully“assembled” within the surgical wound in an “unlocked” (or“partially-unlocked”) configuration, which allows for adjustment of thevarious components prior to final securement and “locking” of theconstruct. Moreover, various embodiments described herein includeaudible and/or tactile indicators or “assurances” to the surgeon and/orstaff that a “temporary” and/or “provisional” connection between variousmodular components has been initiated, with these “temporary” and/or“provisional” connections not requiring removal and/or modificationbefore the pedicle screw system and associated rods can be securelylocked into a desired axial position, angle, and/or orientation. Thedisclosure is also directed to several alternative designs, materialsand methods of assembling polyaxial bone anchor structures andassemblies.

Various embodiments described herein disclose screw (and/or otherfixation element types such as hook, pins and/or loops) and rod fixationsystems incorporating components (including modular and/orinterchangeable components and/or subcomponents) that can be adjustedin-situ and that provide a strong, effective and secure locking of thescrews, rods and/or other fixation elements in a desired configuration,position, orientation and/or angle when desired by a surgeon. Inaddition, the various embodiments significantly reduce the size and/ornumber of components to provide for simpler, more effective, moredurable and/or less cumbersome devices for fixation of anatomicalstructures.

In one exemplary embodiment, a spinal stabilization construct cancomprise a tulip body, a bone screw, a lower saddle or insert, a supportrod, and a set screw. The tulip body may include arms defining a slotand/or channel therebetween (sized for receiving the support rod), abase portion defining an opening to receive a shank portion of the bonescrew and a surface adjacent the opening for supporting the head of thebone screw, a pocket to receive the lower saddle insert and internalthreading to accommodate the set screw. The lower saddle insert mayinclude one or more locking features that secure the insert into thetulip body, and can further include various detent, “snap-fit” and/orfrictional coupling features operable between the support rod and theinsert (within the tulip body) as well as between the bone screw and theinsert (within the tulip body), while allowing relative movement and/oradjustability between the various modular components (even when anchoredto the vertebral bodies) prior to ultimate fixation and/or“immobilization” of the spinal stabilization construct.

In another embodiment, the spinal stabilization system may comprise amonoaxial hook pedicle screw system. The monoaxial hook pedicle screwsystem may include a tulip body having one or more hooked shapedprojections, a support rod, a lower saddle insert, and a set screw. Thehook tulip body may include arms defining a slot and/or channeltherebetween sized for receiving the support rod, a base portiondefining an opening to receive a targeted bone segment, and at least onepocket to receive tabs from the lower saddle insert. Alternatively, thehook tulip body may contain an offset base portion, where the baseportion may be axially distanced away or adjacent to the arms thatdefine a slot and/or channel therebetween. Furthermore, the lower saddleinsert may contain a plurality of frictional or other components thatcan operate to “lock” the insert to the support rod and the hook tulipbody.

In another embodiment, the spinal stabilization system may comprise apolyaxial hook pedicle screw system. The polyaxial hook pedicle screwsystem may include a bifurcated and/or clevised tulip body, a supportrod, a lower saddle insert, a pivotal hook portion, and a set screw. Thehook tulip body may include arms defining a slot and/or channeltherebetween sized for receiving the support rod, a bifurcated and/orclevised base portion defining an opening to receive a pivotal bonehook, and at least one pocket to receive tabs from the lower saddleinsert. The lower saddle insert may contain a plurality of frictional orother components that will operate to “lock” the insert to the supportrod and the hook tulip body. Furthermore, the pivotal hook may include apivot base portion that may be removably connected to the opening of thebifurcated and/or clevised tulip body, and a hook base portion that maybe removably connected to a targeted bone segment. The pivot baseportion may be designed with multiple shape configurations and surfacesto allow desired polyaxial orientation and preciseness (i.e., round,arched, smooth surface, and/or ratcheted surface, etc).

In another alternative embodiment, the spinal stabilization system maycomprise a multi-level transverse connector system. The multi-leveltransverse connector system may include a plurality oftransversely-positioned pedicle screw systems that facilitate anchoringof one or more pedicle screw constructs to various targeted bone segmentconfigurations. Exemplary transverse pedicle screw system components mayinclude a connector body, pivot clamp, rod clamp, clamp screw, springshaft and/or connector rod. The connector rods may be supplied indifferent lengths, shapes and/or sizes to accommodate variousorientations, spinal anatomy and desired correction.

In another alternative embodiment, the spinal stabilization systems maycomprise an angled polyaxial pedicle screw systems. Angled polyaxialpedicle screw systems may include a curved and/or bent support rod inconjunction with multiple tilted and/or angled tulip bodies, associatedlower saddle inserts, and/or set screws. The bent support rodfacilitates the placement of pedicle screw subassemblies in bonystructures adjacent to each other, such as into pedicles of adjacentvertebral bodies, to achieve a desired curvature, preciseness, and/oranchoring of the anatomy. The bent support rod may be already suppliedin a desired bent angle or may be bent in-situ prior to final anchoringof the system. If desired, tilted and/or angled tulip bodies can beprovided that facilitate the placement of pedicle screw subassemblies invery close proximity and/or at relative angles where traditional tulipbody designs may be precluded, such as where the tulip bodies wouldinterfere and/or overlap with each other.

In another alternative embodiment, the various spinal stabilizationsystems described herein could include a variety of tools and/orsurgical techniques for facilitating anchoring and/or attachment of thesystems to targeted bony structures and/or anatomical bone segments.Exemplary tool designs could include screw drivers, support rod cutters,support rod benders and/or drivers that may be supplied as a kit withthe spinal stabilization systems or separately upon request and/or needby the surgeon.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention should be better understood in conjunction withthe detailed description below and the accompanying drawings.

FIG. 1 depicts a front perspective view of one exemplary embodiment of apedicle screw system 100, shown implanted on a vertebral body segment;

FIG. 2 depicts a perspective view of a subassembly of the pedicle screwsystem of FIG. 1;

FIG. 3 depicts an exploded perspective view of the pedicle screw systemsubassembly of FIG. 2;

FIG. 4 depicts a side view of the pedicle screw subassembly of FIG. 2with the tulip head tilted;

FIG. 5 depicts a front view of the pedicle screw subassembly of FIG. 4;

FIG. 6 depicts a magnified cross-sectional side view of the pediclescrew subassembly of FIG. 5, taken along line A-A;

FIG. 7 is an side view of one embodiment of a prior art pedicle screwsystem;

FIG. 8 depicts a magnified side cross-sectional section view along lineO-O of the prior art pedicle screw system of FIG. 7;

FIG. 9 depicts a broken front plan view of the pedicle-screwsub-assembly of FIGS. 4 and 5 with the set screw and support rodremoved;

FIG. 10 depicts an end cross-sectional view along line B-B of thepedicle screw subassembly of FIG. 9;

FIG. 11 depicts a magnified top cross-sectional view along line C-C ofthe pedicle screw subassembly of FIG. 10;

FIG. 12 depicts a broken side view of one embodiment of a pedicle screw;

FIG. 13 depicts a broken side cross-sectional view along line D-D of thepedicle screw of FIG. 12;

FIG. 14 depicts a magnified partial side view of circle F of the pediclescrew of FIG. 13;

FIG. 15 depicts a top view of the pedicle screw of FIG. 12 taken alongline E-E;

FIG. 16 depicts a top perspective view of the pedicle screw of FIG. 12;

FIG. 17 depicts a top view of one embodiment of a tulip body;

FIGS. 18 and 19 depict various side views of the tulip body of FIG. 17;

FIG. 20 depicts a bottom view of the tulip body of FIG. 17;

FIG. 21 depicts a side cross-sectional view of the tulip body of FIG. 18taken along line G-G;

FIG. 22 depicts a magnified top cross-sectional view of the tulip bodyof FIG. 19 taken along line H-H;

FIG. 23 depicts a perspective view of the tulip body of FIG. 17;

FIGS. 24, 25 and 27 depicts various planar views of one embodiment ofthe lower saddle;

FIG. 26 depicts a perspective view of the lower saddle of FIG. 24;

FIG. 28 depicts a perspective view of one embodiment of a set screw;

FIGS. 29 through 31 depict various planar views of the set screw of FIG.28;

FIG. 32 depicts a perspective view of one embodiment of a transverseconnector system;

FIG. 33 depicts an exploded perspective view of the transverse connectorsystem of FIG. 32;

FIGS. 34 and 35 depict various side views of one connector of thetransverse connector system of FIG. 32;

FIG. 36 depicts an enlarged section view of the transverse connectorsystem of FIG. 34 taken along line P-P;

FIG. 37 depicts an enlarged section view of the transverse connectorsystem of FIG. 34 taken along line I-I;

FIGS. 38 and 39 depict various planar views of a transverse connectorsub-assembly, without an associated support rod and connector rod;

FIG. 40 depicts an enlarged section view of the transverse connectorsubassembly of FIG. 38 taken along line J-J;

FIG. 41 depicts an isometric view of a portion of the transverseconnector assembly of FIG. 34;

FIG. 42 depicts a side view of an alternative embodiment of a transverseconnector system without a spring shaft;

FIG. 43 depicts a perspective view of another embodiment of a connectorbody;

FIGS. 44-48 depict various planar views of the connector body of FIG.43;

FIG. 49 depicts a perspective view of one embodiment of a pivot clamp;

FIGS. 50-53 depict various planar views of the pivot clamp of FIG. 49;

FIG. 54 depicts an enlarged cross-sectional view of the pivot clamp ofFIG. 50 taken along line U-U;

FIG. 55 depicts a perspective view of one embodiment of a rod clamp;

FIGS. 56-59 depict various planar views of the rod clamp of FIG. 55;

FIG. 60 depicts a cross-sectional view along line W-W of the rod clampof FIG. 56;

FIG. 61 depicts a perspective view of one embodiment of a clamp screw;

FIGS. 62-64 depict various planar views of the clamp screw of FIG. 61;

FIG. 65 depicts a perspective view of one embodiment of a spring shaft;

FIG. 66 depicts a side view of the spring shaft of FIG. 65;

FIG. 67 depicts an end view of one embodiment of a connector rod;

FIG. 68 depicts a broken side view of the connector rod of FIG. 67;

FIG. 69 depicts an end view of one embodiment of a support rod;

FIG. 70 depicts a side view of the support rod of FIG. 69;

FIGS. 71-74 depicts various views of different configurations of oneembodiment of a multiple transverse connector system, shown in a singleconstruct;

FIG. 75 depicts an exploded side view of one embodiment of a screwdriver assembly;

FIG. 76 depicts a partially-exploded side view of the screw driverassembly of FIG. 75 and a pedicle screw sub-assembly;

FIGS. 77 and 78 depict various planar views of the screw driver assemblyof FIG. 75 and a pedicle screw sub-assembly;

FIG. 79 depicts an enlarged partial view of circle L of the screw driverassembly tip of FIG. 76;

FIG. 80 depicts an enlarged cross-sectional view of the pedicle screwsubassembly of FIG. 77 taken along line M-M;

FIG. 81 depicts an enlarged cross-sectional view along line N-N of thepedicle screw subassembly of FIG. 77;

FIG. 82 depicts an enlarged cross-sectional view of the pedicle screwsubassembly FIG. 78 taken along line Q-Q;

FIG. 83 depicts an enlarged broken cross-sectional view of circle S ofthe pedicle screw subassembly of FIG. 78;

FIG. 84 depicts a sectional view the hook pedicle screw system of FIG.85 taken along line T-T;

FIGS. 85 and 88 depict planar views of one embodiment of a hooksubassembly;

FIGS. 86 and 87 depict planar views of one embodiment of a hook saddle;

FIG. 89 depicts an exploded perspective view of the hook pedicle screwsystem of FIG. 85;

FIG. 90 depicts an end view of one alternate embodiment of an offsethook;

FIG. 91 depicts a perspective view of the offset hook of FIG. 90;

FIG. 92 depicts an exploded perspective view of a prior art pediclescrew system;

FIGS. 93 and 94 depict various views of one embodiment of a prior artinsert;

FIG. 95 depicts an exploded perspective view of another embodiment of apedicle screw system;

FIGS. 96 and 97 depict various views of an alternate embodiment of alower saddle;

FIG. 98 depicts side views of one embodiment of a prior art pediclescrew subassembly, one embodiment of a cannulated pedicle screwsubassembly and one embodiment of a non-cannulated pedicle screwsubassembly;

FIG. 99 depicts an end view of the subassemblies of FIG. 98;

FIG. 100 depicts enlarged cross-sectional views of the prior art,cannulated and non-cannulated pedicle screw subassemblies of FIG. 99,taken along line V-V;

FIG. 101 depicts a side view of one embodiment of a bent support rod;

FIG. 102 depicts a side view of two adjacent pedicle screw subassembliesattached to the bent support rod of FIG. 101;

FIGS. 103 and 105 depict various views of an alternate embodiment of apoly-axial swiveling hook system;

FIG. 104 depicts a cross-sectional view of the poly-axial swiveling hooksystem of FIG. 103, taken along line W-W;

FIG. 106 depicts a perspective view of another embodiment of a pediclescrew system;

FIG. 107 depicts an exploded perspective view of the pedicle screwsystem of FIG. 106;

FIG. 108 depicts a side view of the pedicle screw system of FIG. 106;

FIG. 109 depicts a cross-sectional view of the pedicle screw system ofFIG. 108 taken along line X-X;

FIG. 110 depicts an enlarged section view of circle Y of the pediclescrew system of FIG. 109;

FIGS. 111 through 113 depict various views of an alternate embodiment ofa lower saddle;

FIGS. 114 through 116 depict various views of another embodiment of alower saddle;

FIG. 117 depicts an end view of an alternate embodiment of a bone screw;

FIG. 118 depicts a broken side view of the bone screw of FIG. 117;

FIG. 119 depicts a side view of another embodiment of a pivoting hooksystem;

FIG. 120 depicts a cross-sectional view of the pivoting hook system ofFIG. 119 taken along line Z-Z;

FIG. 121 depicts an exploded perspective view of the pivoting hooksystem of FIG. 119;

FIG. 122 depicts a side view of another embodiment of a pivoting hooksystem;

FIG. 123 depicts a cross-sectional view of the pivoting hook system ofFIG. 122 taken along line AA-AA;

FIG. 124 depicts an exploded perspective view of the pivoting hooksystem of FIG. 122;

FIG. 125 depicts a side view of another alternative embodiment of apivoting hook system;

FIG. 126 depicts a cross-sectional view of the pivoting hook system ofFIG. 125, taken along line AB-AB;

FIG. 127 depicts an enlarged cross-sectional view of circle AC of thepivoting hook system of FIG. 126;

FIG. 128 depicts an exploded perspective view of the pivoting hooksystem of FIG. 125;

FIG. 129 depicts a perspective view of an implant system using analternative extension embodiment of a transverse connector rod clamp;

FIGS. 130 through 133 depict exemplary steps for assembling the pediclescrew subassembly of FIG. 107;

FIG. 134 is a perspective view of an alternative embodiment of atransverse connector;

FIG. 135 is an exploded perspective view of the transverse connector ofFIG. 134;

FIG. 136 is a top view of the transverse connector of FIG. 134; and

FIG. 137 is a cross-sectional view of the transverse connector of FIG.136, taken along line AE-AE of FIG. 136.

DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description, for purposes of explanation,numerous specific details are set forth to provide a thoroughunderstanding of the various embodiments of the disclosure. Those ofordinary skill in the art will realize that these various embodimentsare illustrative only and are not intended to be limiting in any way. Inaddition, for clarity purposes, not all of the routine features of theembodiments described herein may be shown or described for everyalternative embodiment. One of ordinary skill in the art would readilyappreciate that in the development of any such actual implementation,numerous implementation-specific decisions may be required to achievespecific design objectives. These design objectives may vary from oneimplementation to another and from one developer to another, and thevariations thereof are contemplated and included in the presentdisclosure.

Various of the embodiments described herein include features thatfacilitate the assembly of surgical constructs, including surgicalspinal fusion and/or stabilization constructs, which allow the surgeonthe ability to move, reorient and/or otherwise manipulate variousadjustable component features, yet maintain the various adjustablecomponents in a desired position and/or orientation and/or connectionarrangement while in an unfixed condition (i.e., a “non-tightened”assembly). In addition, various embodiments described herein facilitatethe surgeon's assembly and/or adjustment of one or more assembledcomponents within a surgical wound without fear that the components willundesirably separate or otherwise inadvertently disassemble in somemanner.

It should be understood that the term “system,” when referring tovarious embodiment described in the present invention, can refer to aset of components which includes multiple bone stabilization componentssuch as superior, cephalad or rostral (towards the head) componentsconfigured for implantation into a superior vertebra of a vertebralmotion segment and inferior or caudal (towards the feet) componentsconfigured for implantation into an inferior vertebra of a vertebralmotion segment. A pair of such component sets may include one set ofcomponents configured for implantation into and for stabilization of theleft side of a vertebral segment and another set configured for theimplantation into and for stabilization of the right side of a vertebralsegment. Where multiple bone segments such as spinal segments or unitsare being treated, the term “system” may refer to two or more pairs ofcomponent sets, i.e., two or more left sets and/or two or more rightsets of components. Such a multilevel system can also involve stackingof component sets in which each set includes a superior component, aninferior component, and one or more medial components therebetween,which may be interconnected and/or independent from each other.

The superior and inferior components (and any medial componentstherebetween), when operatively implanted, may be engaged or interfacewith each other in a manner that enables the treated spinal motionsegment to mimic the function and movement of a healthy segment, mayalter the relative movement of the various spinal structures in adesired manner and/or may simply fuse the segments such as to eliminatepain and/or promote or enhance healing. The interconnecting orinterfacing systems can include one or more structures or members thatenable, limit and/or otherwise selectively control spinal or other bodymotion. The structures may perform such functions by exerting variousforces on the system components, and by extension on the targetvertebrae. The manner of coupling, interfacing, engagement orinterconnection between the subject system components may involvecompression, distraction, rotation or torsion, or various combinationsthereof. In certain embodiments, the extent or degree of these forces ormotions between the components may be intraoperatively selected and/oradjusted to address the condition being treated, to accommodate theparticular spinal anatomy into which the system is implanted, and toachieve the desired therapeutic result.

Components

In various exemplary embodiments, a spinal fusion system (or otherorthopedic construct, including spinal motion and/or dynamicstabilization constructs) may contain various combinations, sizes andconfigurations of the components described hereafter.

FIG. 1 depicts a front perspective view of one embodiment of a pediclescrew construct 10 incorporating various features of the presentinvention. The construct 10 includes pedicle screw assemblies 100, whichare anchored to vertebral bodies 600 and 601, and a transverse connector200. The pedicle screw assemblies 100 are placed into the pedicle boneof the vertebral bodies 600 and 601 with the use of various standardsurgical instruments through open or minimally invasive surgicalapproaches. The pedicle screw assemblies 100 typically require a screwdriver 300 or other placement device for the initial placement of thebone screw 120 into the bony pedicle. Various embodiments of the presentinvention include unique features providing a novel interface betweenthe screw driver 300 and the bone screw 120 for desirably providing forsecure alignment of the screw into the bone. Also shown in embodiment 10is a transverse connector assembly 200 (see also FIG. 32) that desirablyprovides additional rigidity for the construct, which may be especiallyuseful in spinal fusion procedures where larger constructs (typically oflonger lengths where multiple vertebral bodies and/or levels are fused)or if a vertebral body is “skipped” between fixation levels (i.e., theintermediate vertebral level does not contain a pedicle screw assembly)because of surgeon choice. It is known to those familiar in the art ofspinal fusion that a transverse connector assembly is not alwaysrequired during a fusion procedure, so the fusion construct might onlycontain as few as two pedicle screw assemblies 100 and one support rod150.

For simpler description purposes FIGS. 2-6 and 9-31 will describevarious exemplary components, and interfacing of components in a varietyof ways, of embodiments of a pedicle screw assembly 100 constructed inaccordance with various teaching of this invention. As best seen in FIG.3, an exploded perspective view of the pedicle screw assembly 100reveals a tulip body 110 (also referred to as a coupling device, head,seat or anchor), a bone screw 120 (or various other types of fixationelements), a lower saddle 130 (also referred to as an insert), a supportor connecting rod 150 and a cap or set screw 140.

The bone screw 120 (see FIGS. 12-16) can include a variety of featuressimilar to those of prior art screws (see FIGS. 7-8), including theincorporation of screw threads 1209 and/or a generally symmetrical outerspherical radius 1201, which are similar to screw thread 8203 and outerspherical radius 8202 of prior art screws. In various embodiments, abone screw cannulation 1205 can be provided, which can include a holethrough the entire length of the screw, which might be used in specificsurgeries where the screw is desirably guided along a guide wire (notshown) that travels through the pedicle screw sub-assembly 101, andwhich might also incorporate a lower saddle cannulation 1307 (see FIG.27), if desired. It is well known in the field of spinal surgery thatcomponents 120 and 130 can also have no cannulation (i.e., are solid inthe center—see non-cannulated screw 121 and non-cannulated lower saddle131 in FIG. 100). If desired, the bone screw 120 can also contain asingle self-tapping notch or “tooth” and/or multiple self-tappingnotches 1210 (see FIG. 16) to ease the insertion of the bone screw intoa vertebral body. Bone screws can be manufactured in various lengths,diameters, thread pitches and thread forms, and since these details aregenerally not considered unique to this invention on their individualbases, they will not be further described individually herein.

One unique feature of the bone screw of the present invention includesvarious features incorporated into the head of the bone screw 120, whichcan include a male outer spherical radius 1201 (see FIG. 14) and afemale inner spherical radius 1202, that can be formed concentric toeach other. On the end of the female inner spherical radius 1202 can bedisposed one or more thin tabs 1203, which as shown diverge below thefemale inner spherical radius 1202 (which in various embodiments mayinclude opposing tabs that converge towards each other and/or one ormore non-symmetrical tabs biased towards the central longitudinal axisof the screw) and are desirably formed such that at least one of thethin tabs 1203 have the capacity to “flex” or deflect to some degree,desirably causing one or more of the thin tabs 1203 to have a retainingfunction and/or provide a “friction fit” with a corresponding malespherical radius 1301 of the lower saddle 130 (see FIGS. 10 and 24). Inthe disclosed embodiment, the thin tabs 1203 are separated by slots1208, and while the figures show six slots 1208 and six tabs 1203, avariety of numbers of tabs and slots and tab/slot spacing/orientation(i.e. regularly or irregularly spaced, opposed pairs and/or oddly-spacedtabs or slots such as three equal tabs) may be used and still be withinthe scope of this invention. Also shown is a circular channel 1204 (seeFIG. 14) which can be incorporated into the design to desirably allow agreater amount of free flexible movement of, or clearance for, the thintabs 1203 when the lower saddle 130 is placed into the bone screw 120and tulip body 110 of the sub-assembly 101, such as shown in FIG. 10.

Another unique feature of the present invention includes various drivingfeatures disclosed in various exemplary embodiments described herein,such as driving features 1206 and 1207 (see FIG. 15) disposed on thespherical end of the bone screw 120. In a prior art bone screw (see FIG.8) the bone screw is typically driven by a relatively small diameterfemale hex or hexalobe 8201 (which can include a socket arrangementcommonly referred to as a TORX™ socket and driver, which is commerciallyavailable from Camcar Textron of Providence, R.I., USA). The size of thedriver and socket in these types of arrangements are generallysubstantially smaller than the outer diameter of the screw head, as theouter walls of the socket must be sufficiently thick to withstand therotational torque of the driver, and the size limits of the sphericalradius 8202 must be sufficient to accommodate both the socket and thesurrounding wall thickness. In hard bone of the vertebra 600, the smalldiameter of the female hexalobe 8201 or the mating tip of the prior artscrew driver can strip or even fracture. Moreover, the form of a hex orhexalobe does not provide significant direct driving forces between themale driver and female driving features of the screw, but ratherprimarily relies upon angular contact regions, which can result insignificantly greater stresses on the system. In contrast, the drivingarrangements described in the various embodiments of the presentinvention enables the user to impart forces on both large indirectdriving faces 1207 and large direct driving faces 1206 (see FIG. 15) forinsertion or removal of the bone screw. The faces 1206 and 1207desirably mate with the corresponding faces 3102 and 3104 on thebifurcated tangs 3105 of the screw driver 300 respectively (see FIGS. 79and 80).

When a screw driver 300 is inserted into the pedicle screw sub-assembly101, the bifurcated tangs 3105 can travel into the clearance pockets1109 of the tulip body (see FIGS. 17, 21, 80, 81 and 83) and the faces3103 on the bifurcated tangs 3105 (see FIGS. 79 and 83) desirably comeinto contact with the planar face 1209 of the bone screw 120 (see FIGS.14 and 83). Once this contact is made the male thread 3302 of the sleeve330 of the screw driver 300 can be threaded into the female threads 1104of the tulip body (see FIG. 82). As the sleeve 330 is rotated around theshaft 310 of the screw driver 300, the planar face 3301 of the sleeve330 (see FIG. 79) will come into contact with the planar faces 3101 ofthe shaft 310 (see FIG. 81). Once contact between the two planar faces3101 and 3301 is accomplished, further rotation of the sleeve 330 willdesirably draw the pedicle screw assembly in the direction of the arrow(shown in FIG. 83) until the whole assembly of the pedicle screwsub-assembly 101 and the screw driver 300 are desirably locked togetheras one rigid assembly, making it very easy for the surgeon to insert thebone screw 110 into the vertebral body without the sub-assembly 101falling off of the screw driver 300. Because the components are nowrigidly locked together at the planar faces 1209 and 3103 (see FIG. 83),the bone screw 120 will desirably not tip or angle away from thecenterline axis of the screw driver 300.

In FIGS. 4-6 it can be seen how the tulip body 110 or housing, with itsattached components lower saddle 130, support rod 150 and set screw 140,can desirably be rotated to various conical angles around concentricspherical radii 1201 and 1202 of the bone screw 120, tulip bodyspherical radius 1101 and spherical radius 1301 of the insert, prior tofinal tightening of the pedicle screw assembly 100. In variousembodiments, a friction fit between the thin tabs 1203 and the malespherical radius 1301 of the lower saddle 130 is desirably created bythe positioning, dimensioning and tolerancing of the tabs and/or radiusrelative to each other such that this interaction does not allow thetulip body to “flop around loosely” during surgery (prior to finaltightening of the screw construct) and thereby provide a relativelystable construct (which can be readily moved by the surgeon, if desired)while the surgeon is placing the support rod 150 and set screw 140 intothe pedicle screw sub-assembly 101.

Also shown in the cross sectional view of FIG. 6 are the placements ofthe various components of the pedicle screw assembly 100 in thisembodiment, and how these components interface with each other. Sincethe spherical radii 1101, 1201, 1202 and 1301 can be formedconcentrically, they form an articulating poly-axial construct. Theflexible fingers 1304 of the lower saddle 130 (see FIG. 24) candimensioned, tolerance, engineered and/or manufactured in a size andshape to “squeeze” the support rod 150 and retain the rod when it isplaced into the sub-assembly 101. In various embodiments, the flexiblefingers 1304 will desirably provide an audible and/or tactile feedbackto the surgeon when the support rod 150 “snaps” into the lower saddlerod diameter 1302 from spring pressure of the flexible fingers 1304.Once the support rod 150 is inserted into the lower saddle 130,frictional forces (at least in part due to the presence and/or pressureof the flexible fingers 1304) keep the rod from slipping and/orsignificantly moving in the lower rod diameter 1302. However, thespacing and/or pressure between the flexible fingers 1304 desirablyallows the surgeon to easily slide and/or otherwise move the support rodto an optimal and/or desired position. Those skilled in the art wouldcomprehend that such a unique retention feature of the invention couldbe accomplished using a variety of alternative shapes and/or sizes ofretention members, as well as various forms of lower saddles. In variousadditional embodiments, the retention features described herein may beincorporated into prior art designs, creating designs such as shown inFIGS. 95-97, where another exemplary embodiment 900 of the presentinvention is depicted with a lower saddle or insert 931 incorporatingflexible fingers 9314 (see FIG. 96) or in alternative embodiment theflexible fingers could possibly be removed from the lower saddle 130 andadded (in an embodiment not shown) directly to the tulip body 110.

Once the pedicle screw sub-assembly 101 and support rod 150 are in adesired position and/or orientation, the surgeon can then thread (seeFIG. 6) the male thread 1404 of the set screw 140 (see FIG. 30) into themating female threads 1104 of the tulip body (see FIG. 21). When theplanar face 1401 of the set screw 140 (see FIG. 31) comes into contactwith the support rod diameter 1501 (see FIG. 69) the pedicle screwassembly 100 becomes a complete subassembly. When the surgeon hascompleted all the placements of pedicle screw subassemblies 100 andsupport rods 150, the surgeon can then perform a final tighteningsequence of the set screws 140, using the female hex 1402 with anappropriate hex screw driver to a final pre-determined torque value.Those skilled in the art should appreciate that the female hex 1402arrangement described herein, along with the set screw 140, could beformed in various alternative shapes, such as a hexalobe (Torx), asquare, a slotted, a cross or other shapes.

Various prior art components, including simplified versions of screwcomponents depicted in patents by Sherman (U.S. Pat. No. 5,879,350),Farris (U.S. Pat. No. 6,485,491), Biedermann (U.S. Pat. No. 6,835,196),Jeon (U.S. Pat. No. 6,905,500 and Konieczynski (U.S. Pat. No. 7,087,057)are shown in FIGS. 7, 8, 92, 93 and 94, which are utilized ascomparisons to demonstrate various unique features of the variousembodiments of the present invention. The prior art pedicle screwassemblies include many similar component parts, however the specificdesign and/or features of many of these components differs significantlyfrom the features of many embodiments described herein, which caninclude (but are not limited to) unique screw driving features 1206 and1207, thin tabs 1203 and lower saddle flexible fingers 1304 (asdescribed in various locations of the description herein). Those ofordinary skill in the art will understand that the flexible 1304 fingersof the lower saddle (or other features) might alternatively be designedintegrally into an embodiment of the tulip body or housing, and thus notbe directly attached to the lower saddle insert 130.

FIG. 11 is a sectioned view along line C-C of FIG. 10 which depicts aportion of the top of the bone screw 120 along with sections of thelower saddle 130 and tulip body 110. Also seen in this sectioned vieware the planar surfaces 1306, which are formed in this embodiment to bea predetermined distance apart 1305 that is desirably less than theinner diameter of the tulip body 110, thereby allowing for sufficientclearance for the tangs 3105 of the driver 300 to contact the bone screw120.

In FIGS. 17-21, various planar views of the tulip body 110 show otherfeatures of this invention. One or more clearance surfaces 1107 (whichmay be symmetrical and/or nonsymmetrical—see FIGS. 18 and 19) can bedesigned to allow closer placement of adjacent bone screw sub-assemblies100 (see FIG. 102), especially where the use of an angular support rodis contemplated and/or desired, such as when using a support rod 150that includes a bent area 1503 (see FIG. 101). In FIG. 21, where asection view along line G-G of FIG. 18 is depicted, the two symmetricallower saddle radial pockets 1103 are shown and also are shown in theenlarged section view of FIG. 22. In the disclosed embodiment, the lowersaddle radial pockets 1103 are not necessarily concentric, as theircenterlines can be offset (as shown in FIG. 22) and they desirably matewith the symmetrical radial surfaces 1303 of the lower saddle 130,desirably having centerlines that are also offset with each other (seeFIGS. 24 and 27). These non-concentric mating surfaces 1103 and 1303 canbe designed in this manner so as to inhibit and/or prevent rotation whenassembled together as shown in FIG. 11. FIG. 18 depicts symmetricalattachment pockets 1105 on each side of the tulip body 110. Theseattachment pockets 1105 are triangular in shape (although other shapescould function in a similar manner) to allow a mating male triangulartab (not shown) to lock onto the tulip body 110 and manipulate it intothe desired position by the surgeon. Designed into the attachmentpockets 1105 is an upper radius 1110 that has a clearance diameter 1106which can accept an instrument with mating male round tabs which willdesirably not immovably lock onto the tulip body 110 because thetriangular planar surfaces 1105A, 1105B and 1105C are not necessarilyengaged with the instrument, but may rather allow the surgeon to use theupper radius 1110 as a pivot point for a fulcrum or attachment ofvarious other instruments to assist with the physician's manipulatingthe position of the construct.

FIGS. 28-31 depict perspective and planar views of one exemplary setscrew 140 which shows a thread (which may be an industry standard squarebuttress thread or other thread form, if desired). The set screw 140 hasa planar surface 1401 that desirably contacts the rod diameter 1501 ofthe support rod 150 when assembled (see FIGS. 6 and 69). When the setscrew 140 is threaded to a specific torque value in the tulip body, thevarious components of the sub-assembly 100 (see FIG. 6) desirably becomelocked together. Also shown in these figures is an optional throughdiameter 1403, which can be used in conjunction with a guide instrumentto slide the set screw 140 into position. Those of ordinary skill in theart should understand that the set screw 140 can also be manufacturedwithout the diameter 1403, without impeding the function of the planarsurface 1401.

FIGS. 106-110 depict various views of one alternative embodiment of apedicle screw system, in which a lower saddle 132 includes a pluralityof connecting or “provisional attachment and/or connection” elementsthat attach the lower saddle or insert 132 to the tulip body 132, to therod 150, and to the bone screw 122. Desirably, these various connectingprovisional attachment elements connect various components of thepedicle screw system to inhibit and/or prevent disassembly of theconnected components, yet allow some relative movement between theconnected components. Moreover, the provisional attachment elementsdesirably provide various clamping, resisting and/or frictional forcesto inhibit and/or prevent undesirable movement between the connectedcomponents, such as “floppiness” and/or unwanted movement of thecomponents prior to securing on the targeted bone segment and/or priorto final tightening of the construct, yet allow the physician theability to manipulate, move and/or reorient the various attachedcomponents (relative to each other) by applying some nominal amount ofexternal force. Desirably, the provisional attachment elements will notinterfere with the final fixation and tightening of the pedicle screwcomponents, which can desirably create a rigid construct and/orsubcomponent, as desired.

As best seen in FIGS. 111 through 113, the lower saddle or insert 132can include various “provisional” or “temporary” attachment elementssuch as flexible fingers 1321 and/or thin spring arms 1325. In thedisclosed exemplary embodiment, the lower saddle 132 can include atleast one flexible finger 1321 extending upward from the lower saddlebody (in the disclosed embodiment, two such fingers are shown). Theflexible fingers 1321 may include an outer surface 1329, an inner rodseat surface 1326 and optional retention tabs 1327. The flexible fingers1321 can be desirably spaced apart to form a channel or opening 1326that is sized to fit a support rod 150. The support rod 150 can beinserted in the channel or opening 1326 and positioned in the inner rodseat surface 1326. In the disclosed embodiment, the inner surface of theflexible fingers include optional extensions or retention tabs 1327,which desirably project inward from the flexible fingers into the innerchannel 1326, where the spacing between the retention tabs is desirablysmaller than an outer diameter of the support rod 150. When the supportrod 150 is first inserted into the opening or channel 1326, the rod willcontact the retention tabs 1327, and additional pressure on the rod fromthe surgeon's hand (with continued insertion of the rod) will desirablyflex or bend outward the flexible fingers 1321 to some extent, with therod sliding past the retention tabs 1327. Once the support rod 150passes the retention tabs, the fingers will desirably slide or “snap”back towards their original position, with the rod fully seating intothe opening or channel 1326 and the flexible fingers 1321 desirablyreturning at or near their original positions. Once the rod is in adesired position within the channel 1326, the flexible fingers 1321 can(if desired) place a compressive force on the outer surface of thesupport rod 150 (to desirably inhibit and/or control movement of the rodalong its longitudinal axis), and the retention tabs 1327 and associatedflexible fingers 1321 will desirably retain the support rod 150 withinthe channel 1326. Desirably, this arrangement will serve to “hold” therod with sufficient force to inhibit uncontrolled longitudinal movementrelative to the lower saddle 132, yet allow longitudinal movement of therod relative to the lower saddle 132 and/or housing upon urging from thephysician.

In various embodiments depicted herein, the lower saddle 132 willdesirably fit into and be secured within the tulip body or housing 112.As best seen in FIGS. 110 and 114, the lower saddle 132 can include oneor more flexible tabs 1322 on an outer surface, which can desirably fitinto corresponding lower saddle radial pockets 1122 (see FIGS. 21 and22) of the tulip body 112. Alternatively, the one or more flexible tabs1322 (and/or some or all of the outer surface of the lower saddle body,if desired) could frictionally fit and/or “wedge” against one or moreinner surfaces of the tulip body 112, if desired. In various alternativeembodiment, the flexible tabs 1322 and/or lower saddle pockets 1103could include one or more flat or planar surfaces which interact, “snap”and/or otherwise lock when the lower saddle 132 has been rotated into adesired position within the tulip body 112. In various otherembodiments, the flexible tabs 1322 and/or lower saddle pockets 1103could include surface features (i.e., patterns and/or surface roughness)on one of more interacting surfaces to increase frictional attachment tothe tulip body 112.

In various embodiment, the flexible tabs 1322 are desirably spaced apartfrom the flexible fingers 1329, with a gap or opening 1328 between theflexible fingers 1329 and flexible tabs 1322 which desirably allows theindependent flexing and/or compression of either or both of the flexiblefingers 1321 and/or the flexible tabs 1322. In one exemplary embodiment,the gap or opening 1328 may not extend as deep or as wide as depicted inFIG. 111, which may result in some restriction in the flexion and/orcompression of the flexible fingers 1321 and/or flexible tabs 1322,while in others the gap 1328 may equal the depth of the channel 1326(see FIG. 111) or may exceed the depth of channel 1326.

In various embodiments, the lower saddle 132 may be designed with one ormore (i.e., at least two, in the various disclosed embodiments) springarms 1325 on a lower portion, such as shown in FIGS. 110 and 113, whichdesirably extends at least partially around a circumference of the bonescrew and “grips” the male spherical diameter 1221 of the bone screw,desirably retaining the head of the bone screw and also creating somelevel of compression force and/or frictional resistance between thelower saddle 132 and the head of the bone screw 122. In variousembodiments, the thin spring arms 1325 of the lower saddle 132 can forma portion of a female spherical diameter 1323 formed on a lower portionof the lower saddle 132, with the male spherical diameter 1221 of thebone screw 122 being moveably secured within the female sphericaldiameter 1323, where frictional forces and/or tension forces ofinteracting friction surfaces 1324 contacting the spherical diameter1221 of the bone screw 122 creates a resistance that desirably inhibitscompletely free movement of the bone screw 122 relative to the lowersaddle 132, yet allows relative movement between the bone screw and thelower saddle when induced by sufficient force from the surgeon. Thespring arms 1325 (as shown in FIG. 113) and/or other areas of the lowersaddle 132 may be designed to include various channels or openings withan equivalent and/or smaller dimension than the spherical diameter 1221of the bone screw 122, which could allow for deflection of the thinspring arms 1325 such that they could pass over the larger sphericaldiameter 1221 of the bone screw 122 with little or no resistance, yetallow sufficient frictional resistance forces to accomplish the variousobjectives of the present invention. The thin spring frictional arms1324 may include an additional frictional projecting lip 1324 (see FIG.114) that can extend perpendicular and/or outwardly from the surface ofthe thin spring arms 1324 that could optionally provide additionalclamping force onto the spherical diameter 1221 of the bone screw 122.

The resulting resistance to relative movement between the lower saddleand the head of the screw desirably prevents the tulip body 112 from“flopping around” relative to the screw head after the screw assembly isinserted into the vertebral body and the insertion tool(s) is removed.This system can allow a surgeon to adjust the orientation, movementand/or angulation of the bone screw 122 relative to the tulip body 112and have such adjustment maintained in a desired position while thesurgeon is anchoring additional bone screws 122 into the targeted bonesegment and/or placing additional instrumentation onto the spinalconstruct.

In one exemplary embodiment, the lower saddle 132 may be retained in thetulip body 111 through the interaction of symmetrical lower saddleradial pockets 1112 and symmetrical radial surfaces 1322 (see FIG. 110)in a manner similar to various ones described earlier for the lowersaddle 130 and tulip body 110, with the two symmetrical lower saddleradial pockets 1103 engaging with the corresponding symmetrical radialsurfaces 1303 of the lower saddle 130. This embodiment 905 can alsoincorporate flexible fingers 1321 on an upper surface of the lowersaddle 132 to desirably maintain pressure on a support rod 150, in amanner similar to the retention of the bone screw by the flexiblefingers 1304 of the lower saddle 130. Various views of the flexiblefingers 1321, flexible tabs 1322, female spherical diameter 1323,friction surfaces 1324 and spring area 1325 can be seen in FIGS.111-113.

In various alternative embodiments, frictional and/or other forcesinteracting between individual elements may be designed into the systemto prevent and/or inhibit the tulip body 111 from flopping aroundrelative to the bone screw (in an uncontrolled and/orpartially-controlled manner), with the various resistance forcespotentially adjusted by designing different configurations of frictionalarms, thin spring arms and/or friction projecting lips (or other similarfeatures). FIG. 114 depicts one alternative embodiment of a lower saddle133, where the lower saddle 133 may be designed with thin springrecessed arm surfaces 1335 to allow relatively less spring pressure thanthe spring area 1325 of lower saddle embodiment 132. The thin springrecessed arm surfaces 1335 may be designed to a configuration that mateswith spherical diameter 1221 of the bone screw 122 (as shown in FIG.110). The thin spring recessed arm surfaces 1335 may include an optionalfrictional projecting lip 1324 for additional frictional forces.

To initially assemble a pedicle screw subassembly incorporating variouslower saddle embodiments (embodiment 905 of FIG. 106 used as an example)with a corresponding tulip body 111, the male spherical head 1221 (seeFIG. 107) of a pedicle screw 122 can first be inserted into a femalespherical diameter 1111 of the tulip body 111 as shown in FIG. 130. Nextthe flexible fingers 1321 of the lower saddle 132 are perpendicularlypositioned to the symmetrical openings 1118 (see FIG. 131) of the tulipbody and inserted into the tulip body 111 till the female sphericalradius 1323 of the lower saddle 132 contacts the male spherical 1221 ofthe pedicle screw 122 as shown in. The lower saddle 132 can then beturned clockwise and/or counterclockwise (i.e., by rotating 90 degrees),thereby inducing the flexible tabs 1322 to deflect inward until theflexible tabs 1322 have mated with the lower saddle radial pockets 1112.A potential audible sound may occur and/or an increase of friction mayoccur due to a wedging action. The final placement can be seen in FIGS.132-133. Of course, in alternative embodiments, the securement of thesaddle body within the tulip body may be accomplished by wedging theouter surfaces of the lower saddle against the inner surfaces of thetulip body, if desired (which may or may not include locking tabs orother features).

In various alternative embodiments, the pedicle screw 122 and lowersaddle 132 may first be assembled (i.e., by insertion of the malespherical head 1221 into the female spherical radius 1323 of the lowersaddle 132), followed by insertion and securement of this subassemblyinto the tulip body 111 (in a manner similar to that previouslydescribed).

In various embodiments, the diameter of the pedicle screw head willtypically be larger than the diameter of the lower opening 1110 of thetulip body, although in alternative embodiments the pedicle screw headmay be equal to or smaller than the diameter of the tulip head loweropening (which could allow for the pedicle screw to be first insertedinto the bone, without the attached tulip head and saddle, and then thetulip body and saddle body could be inserted subsequently).

One significant feature of the various embodiments described herein isthe ability to “tighten” or immobilize the various elements of thepedicle screw subassembly once the components are in a desired positionand/or orientation. Desirably, once a rod has been seated into the lowersaddle 132 of an implanted screw assembly, a set screw 140 can beintroduced into the tulip body and rotated/tightened. Desirably,advancement of the set screw will push the rod downward into the tulipbody, which compresses the insert downward into the tulip body. In turn,the downward movement of the insert sandwiches the head of the pediclescrew between the female spherical diameter 1323 of the insert and aninner surface of the tulip body spherical radius 1101 (see FIG. 6, forexample). Desirably, these various compressive forces significantlyincrease the friction between the various components of the subassembly,effectively immobilizing and/or locking them relative to one another.

In various embodiments, the insert can comprise a variety of materials,but in at least one embodiment the insert comprises an unalloyed orcommercially pure Titanium (Ti). This type of material can beparticularly useful in orthopedic constructs due to its low biologicalreactivity. In addition, when used in an insert (such as describedherein), the compressive forces induced by rotation of the set screw maybe strong enough to induce some portions of the insert material to“flow” or otherwise deform to a limited degree, possibly bonding or“cold welding” various components and significantly increasing the fusedstrength of the subassembly construct.

FIGS. 115 and 116 depict an alternative embodiment of a lower saddle134, where the lower saddle 134 may include slots 1345 to allow lessspring pressure (and/or rotation resistance) than the spring area 1325of lower saddle embodiment 132. The thin spring slotted arms 1335 mayinclude an optional frictional projecting lip 1324 for additionalfrictional forces. In this embodiment, the flexibility of the springarms 1345 can be enhanced, even where the spring arms are significantlythicker than those of the embodiment of FIGS. 111-113 or FIG. 114.

Those of ordinary skill in the art should understand that the number ofslots 1345, number of friction surfaces 1324 or any combination ofrecessed surfaces 1335 or non-recessed surfaces, in variouscombinations, could be possible with varying degrees of effectivenesswhile significantly retaining the spirit of the present invention. Invarious alternative embodiments, the thin spring arms on the variouslower saddle embodiments described herein might may be designed onopposite sides, adjacent to each other or some angle distanced apart onthe circumference of the lower saddle. In additional embodiments,non-symmetrical distributions of spring arms might be utilized.

In various embodiments, a series of pedicle screw subassemblies ofdifferent sizes and/or shapes (and associated support rods and/or othercomponents) could be assembled and provided in a kit. A surgeon couldthen select a desired pedicle screw subassembly, and drive the screwshank into a targeted bony feature using a surgical tool, such as thescrew driver having a mating male driving feature that mates with thefemale driving feature 1221 on the bone screw 122, such as describedherein. The surgeon may repeat this approach for additional pediclescrew subassemblies, and then the surgeon could manipulate the tulipheads of one or more subassemblies (as described herein) to align thetulip heads to receive one or more connecting rods. The connectingrod(s) could be placed, and the surgeon could further manipulate thealignment and/or orientation of the various system components. Once in adesired alignment, the surgeon could fixate the various components byplacing set screws onto the tulip heads and advancing them in a knownmanner. If desired, the surgeon may manipulate various component of thesurgical construct as desired, without fear of the various untightenedcomponents disassembling and/or separating under such manipulation. Oncethe entire construct is tightened and “locked” in this manner, thesurgical wound can be closed and the surgery completed.

FIGS. 32 and 33 depict a perspective and an exploded view of anotherembodiment of the invention, which is a transverse connector assembly200. Various types of transverse connectors have been previouslyconnected to pedicle screw constructs, but such subsystems have beenloose fitting and cumbersome to put into place. In the exploded view ofthe transverse connector 200 assembly the following components areincluded: connector bodies 210, pivot clamps 220, rod clamps 230, clampscrews 240, spring shafts 250 and a connector rod 260.

Once various pedicle screw assemblies 100 and support rods 150 have beenplaced in the bone of the targeted vertebra, a connecting rod 260 of anappropriate length to span two or more support rods can be chosen (seeFIGS. 1 and 71). Referring to FIGS. 34-41, two transverse connectorsub-assemblies 201 (see FIGS. 38-39) can be placed on the ends of theconnecting rod 260. The fit between the connecting rod diameter 2601(see FIG. 67) of the connecting rod 260 and the connecting rod apertures2302 (see FIG. 60) of the rod clamp 230 can be a spring or friction fitcreated by channel 2305, between points a and b (see FIG. 58), thatallows the rod clamp 230 to be pushed onto and/or “snapped” over theconnecting rod 260 (i.e., using finger pressure) yet remain secureenough on the rod to not allow the transverse connector sub-assemblies201 to freely rotate and/or move (i.e., under their own weight) fromtheir desired position once in place on the connecting rod 260.

In the disclosed embodiment, before the transverse connector assembly200 is placed onto the support rods 150, the spring shaft 250, which cancomprise a flexible super-elastic shape memory metal or other flexiblematerial, is in a straight or unrestrained condition, such as shown inFIGS. 39 and 40. When it is in this position, the rod clamp radius 2203of the pivot clamp 220 (see FIG. 52) can violate, or swivel past thecircle, shown as ØA in FIG. 40. The pivot diameter 2201 of pivot clamp220 (see FIG. 49) rotates in the pivot channel 2102 (see FIGS. 44 and46) of the connector body 210 while the flanges 2206 (see FIG. 49) oneach end of the pivot diameter 2201 are restrained axially by the planarsurfaces 2207 of the pivot clamp 220 (see FIG. 50) and the planar walls2107 (see FIG. 44) of the connector body 210. On the connector body 210there can be included two tangent walls 2109 in the pivot channel 2101,adjacent to the screw pocket 2104, (see FIG. 44) that can be straightwhen the pivot clamp 220 is placed in the channel 2102 but are that canbe swaged or bent in area 2103 (see FIG. 41) to prevent the pivot clamp210 from accidental displacement from the connector body 210 if the rodclamp 220 and clamp screw 240 are removed from the transverse connectorsub-assembly 201. Prior to installing the pivot clamp 220 into theconnector body 210 the spring shaft 250 can be inserted into thecounter-bore 2205 and spring hole 2204 of the pivot clamp 220 (see FIG.54). The spring shaft 250 is desirably sufficiently flexible to fit overthe sides of the connector body 210 and drop into spring pocket 2105(see FIG. 46) of the connector body (see FIG. 37). Those skilled in theart should understand that a hole (see spring hole 2115 in FIG. 135) orother feature can be used to retain the spring shaft 250 in position inlieu of the spring pocket 2105. With this arrangement, the pivot clamp220 will now desirably rotate into the position shown in FIGS. 39 and 40when the spring shaft 250 is in its normal, relaxed, position alongsidewall 2106 (see FIG. 46).

In another embodiment of the transverse connector 22 (see FIGS. 134-137)the channel 2101 can be replaced with a through diameter 2111 in theconnector body 211 and the pivot clamp can be a multiple piece assemblyconsisting of a pivot shaft 221A and pivot clamps 211B and 221C wherethe diameter 2211 of the pivot shaft 221A rotates in the throughdiameter 2111. The pivot clamps can be welded onto the pivot shaft atmating surfaces 2212 and 2213 but those skilled in the art shouldunderstand that there other methods and means of attachment such asinterference fits, screws and/or bonding that are also within the scopeof this invention.

The surgeon can now take the complete transverse connector assembly 200and snap the assembly onto the previously implanted support rods 150.This is accomplished by the presence of the support rod 150, whichapplies pressure to the flanges 2206 of the pivot clamp 220 and uponpressure from the surgeon's advancement of the assembly causes the pivotclamp 220 to rotate, thus flexing the spring shaft 250 as shown in FIGS.35 and 37. In this orientation, the spring shaft 250 should now applyspring pressure to the pivot clamp 220, thereby allowing the rod toslide into and along the channel 2108 of the connector body 210 (seeFIG. 46), which also desirably “pinches” and/or frictionally capturesthe support rod's diameter 1501 between radial surfaces 2203 and 2101 ofthe pivot clamp 220 and connector body 210 (at least partially due tothe spring pressure from the spring rod 250—see FIG. 37), thus keepingthe transverse connector sub-assemblies 201 in a desired position.Alignment of the transverse connector assembly 200 can be easilyaccomplished, as each transverse connector sub-assembly 201 can assume avariety of individual rotational axes X, Y and Z (see FIG. 74), therebyallowing an essentially infinite number of positions. FIGS. 71 through74 demonstrate various exemplary contortion capabilities of theconnection systems described herein.

Once various components of a transverse connector sub-assembly have beenpreassembled (but not tightened, if desired), the surgeon can easilyslide various components of the transverse connector sub-assemblies 201into a final desired position and/or orientation. Once the transverseconnector assembly 200 is in place, the surgeon can tighten the clampscrew 240 on each subassembly, and the surface 2401 (see FIG. 63) willapply pressure to the rod clamp 230, thereby locking the connecting rod260 in place while simultaneously applying further downward pressureonto the pivot clamp contact face 2301 (see FIG. 60) and pivot clamplever arm radius 2202 (see FIG. 52), which locks the transverseconnector sub-assemblies 201 onto the support rods 150. One exemplaryfinal locked position is shown in FIG. 37.

If desired, a shoulder 2402 of the clamp screw 240 (see FIG. 63) can beprovided that gives additional strength to the female hexalobe 2405(should it be desired), which can fit into a counter-bore 2303 (see FIG.60) of the rod clamp 230 when assembled. If desired, as shown in FIGS.135 and 137, mating countersinks 1322 and 2411 can be used to reduce theheight of the construct. If desired, there can also be pilot diameter2404 on the clamp screw, if desired, to help align the male thread 2403(see FIG. 63) and female thread 2105 (see FIG. 43) of the connector body210. To those of ordinary skill in the art it should be understood thatthe various features 2402, 2404 and 2303 (see FIGS. 63 and 60) could beprovided in various combinations (or need not be present, if desired)for the invention to perform as intended. It should also be understoodthat hexalobe 2405 (FIG. 62) or other features or shapes, like ahexalobe (Torx), square, slotted, cross or other shapes, could beutilized. It should be apparent to those skilled in the art that thespring ring 270 which is used to retain the rod clamp 232 on the screw241 can be any number of various features such as bendable tabs or a pinin groove feature in order to retain the spring clamp 232 on the screw241 while simultaneously allowing free rotation of the screw 241 in therod clamp 232.

FIG. 2 depicts a side view of another additional embodiment of a singletransverse connector assembly 300, where no spring shaft is provided,but the clamping and contortion features of the system are substantiallysimilar to those previously described.

FIG. 129 depicts another additional embodiment of a single transverseconnector assembly 21, where a rod clamp 231 accepts a support rod andis used to extend a construct to additional levels without requiringdisassembly of an existing construct and/or using a longer support rod.This embodiment would potentially be very useful in a revision surgerywhere the physician desires to attach additional pedicle screwassemblies 100 to a prior construct from an earlier surgery whileleaving the implants from the original surgery in place.

FIGS. 84-91 depict another embodiment of a hook assembly 400 constructedin accordance with various teachings of the present invention, whichincludes hooks or other connection features to attach various componentsto bony members of the spine or other anatomical locations. Variousdisclosed components that could be utilized with this embodiment includea hook body 410 having a single hook 4102; a hook body 420 having abifurcated hook 4203; an offset hook body 450 which could includevarious offsets 4501 and various hook forms (i.e., including bifurcatedand/or single 4402 and/or other arrangements). In addition, the variousembodiments can include a lower saddle 430 and a set screw 440, whichfacilitate attachment to a support rod 150.

Spinal surgeons have used various hook-based systems to attach to bonyelements of the spine for many years, but positioning the hooks in placeand them maintaining the positioning and/or alignment of the hooks in aspecific location has often been difficult, if not impossible, usingprior art systems. Various features of the disclosed hook assemblysystem 400 can employ similar friction retention and “snap fit”techniques onto a support rod 150 as the various pedicle screwembodiments described previously. For example, the lower saddle 430 ofthe hook assembly 400 can include similar flexible fingers 4304 formedas part of the lower saddle or insert 130 (see 1304 on FIG. 24), whichcan be designed and sized to squeeze a support rod 150 and hold the hookassembly 400 securely in place when it is placed onto the support rod.The flexible fingers 4304 can provide an audible and tactile feedback tothe surgeon, if such as desired, when the support rod 150 “snaps” intothe lower saddle 430 from spring pressure of the flexible fingers 4304.Those of ordinary skill in the art should understand that variousfeatures of the lower saddle 430 and/or the flexible 4304 fingers couldbe formed integrally into the hook body, without necessarily requiringan additional component such as the lower saddle 430. In the disclosedembodiments, once a hook assembly 400 is placed onto a rod, the frictionand other resistance forces induced by the pressure of the flexiblefingers 4304 will desirably retain and keep the rod from slipping in thelower saddle 430. Desirably, however, the resistance forces and/orpressure does allow the surgeon to easily move the lower saddle 430 toan optimal position relative to the rod, either using his fingers orwith instruments attached to the sides of the hook body via a similarpocket design (or other connection feature) as described in connectionwith the attachment pockets 1105 on the tulip body 110. Once placed in adesired position and/or orientation, the surgeon can then place a setscrew 440 to lock the hook in place.

Though not shown it is understood that the connecting rod 260 can be thesame diameter as the support rod 150 to extend the system and attachadditional pedicle screws.

Additional Alternative Configurations

FIGS. 103-105 depict various views of one embodiment of a pivoting orswiveling hook pedicle screw hook system, which may comprise a tulipbody 110, a lower saddle 130, a set screw 140 a support rod 150 and aswiveling hook 510. The swiveling hook 510 may include an inner surfacereceiver base 5108 that can receive the lower saddle insert 130, and/orat least one or more frictional elements or “fingers” 5106 which candesirably engage and/or inhibit relative motion between the lower saddleinsert 130 and the receiver base 5108. Also, the swiveling hook may beadapted with a hook 5104, where the inner hook surface 5102 may beradiused to allow for anchoring to the targeted anatomy.

FIGS. 119-128 depict additional alternative embodiments of a polyaxialhook pedicle screw system constructed in accordance with variousteachings of the present invention. FIGS. 119-121 depict anotherembodiment of a swiveling hook pedicle screw system 505, which mayoptionally include a swivel or pivot feature having a clevised orbifurcated tulip body 112 with an upper portion base 1122 and a lowerportion base 1123. The lower portion base 1123 may include bifurcatedarms 1121 that are distanced apart to form a channel or opening toreceive the pivot head 5111 of the hook 511. The pivot head 5111 may besecured by means of a pivot pin 251. The hook assembly 505 can beretained on the support rod 150 by the flexible fingers of lower saddle135.

In this embodiment, the pivot head 5113 and 5123 may be designed withsmooth surfaces 5111 and 5112 (as shown in FIGS. 121 and 124respectively) to allow for continuous and uninterrupted orientationand/or movement, or such surfaces may be textured to increase resistanceto movement and/or securement on locked into position. In variousalternative embodiments, the pivot head may include a variety ofradiuses and/or configurations, such as a circular radius pivot head5112 (as shown in FIG. 120) and/or an arched radius pivot 5121 (as shownin FIG. 123), where the arched radius 5121 may have a transition regionor necked region 5124. When the set screw 140 is tightened in its finalassembly, a downward force is desirably translated through the supportrod 150, the lower saddle 136 and the arched pivoting hook 512.

In various alternative embodiments, the pivot head 5132 may includemechanized locking and/or “ratcheting” features to desirably controland/or limit the orientation and/or movement of the various components,such as shown in FIG. 128. FIGS. 125-128 depict one alternativeembodiment of a polyaxial hook pedicle screw system 507 with a ratchetedpivot head 5132. The ratcheted polyaxial pedicle screw system 507 mayalso include a clevised and/or bifurcated tulip body 114, whichdesirably retains a pivotal hook 513 by means of a pivot pin 251. Theratcheted polyaxial hook pedicle screw system 507 can be retained on thesupport rod 150 by the flexible fingers of lower saddle 137. When theset screw 140 is tightened in its final assembly, a downward force istranslated through the support rod 150, the lower saddle 137 and theratcheted pivoting hook 513. The ratcheted pivoting hook 513 may belocked into various positions by female radial teeth 1371 of the lowersaddle 136 and the mating male radial teeth 5131 of the pivot head 5132.The male radial teeth 5131 and the female radial teeth 1371 of the lowersaddle 136 may be distanced apart to achieve a desired control of angle,orientation and/or movement. For example, the male radial teeth 5131 andthe female radial teeth 1371 may have 1 mm, 2 mm, or 3 mm distanceand/or angular measurements may be used (i.e., 5, 10, 15 or 20 degrees),which may be notched or printed on the pivot head 5132.

If desired, various features of the alternative embodiments of apolyaxial hook pedicle screw system, including those shown in FIGS.119-128, may be designed by combining some or all the shapes,configurations and surfaces discussed above. For example, the ratchetedpivot head 5132 may be designed with a circular radius pivot head 5112(as shown in FIG. 120) instead of an arched radius pivot head. The hookpedicle screw system may also include a uniaxial design as well.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The various headings and titles used herein are for the convenience ofthe reader, and should not be construed to limit or constrain any of thefeatures or disclosures thereunder to a specific embodiment orembodiments. It should be understood that various exemplary embodimentscould incorporate numerous combinations of the various advantages and/orfeatures described, all manner of combinations of which are contemplatedand expressly incorporated hereunder.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention are to be construed to cover boththe singular and the plural, unless otherwise indicated herein orclearly contradicted by context. The terms “having,” “including,” and“containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted. Recitation ofranges of values herein are merely intended to serve as a shorthandmethod of referring individually to each separate value falling withinthe range, unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., i.e., “such as”) provided herein, is intended merely tobetter illuminate the invention and does not pose a limitation on thescope of the invention unless otherwise claimed. No language in thespecification should be construed as indicating any non-claimed elementas essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventor for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventor expects skilled artisans to employ such variations asappropriate, and the inventor intends for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context

1. A spinal connecting device for coupling a first spinal rod to asecond spinal rod, comprising: a head assembly including a first rodclamp, the first rod clamp having at least two sidewalls forming a firstspinal rod receiving passage, with a clamp spacing between the at leasttwo sidewalls at a location proximate to a distal end of the at leasttwo sidewalls being less than a diameter of the first spinal rod; and aconnector body including a second rod clamp, the second rod clampincluding at least one fixed wall and one moveable wall forming a secondspinal rod receiving passage, the moveable wall adjustable between afirst position and a second position, wherein a spacing between a distalportion of the fixed wall and a distal portion of the moveable wall whenthe moveable wall is in the first position is less than a diameter ofthe second spinal rod and a spacing between a distal portion of thefixed wall and a distal portion of the moveable wall when the moveablewall is in the second position is equal to or greater than the diameterof the second spinal rod.
 2. The spinal connecting device of claim 1,wherein the connector body is rotatably coupled to the head assembly. 3.The spinal connecting device of claim 2, wherein at least one of the atleast two sidewalls is capable of flexing to a first flexed position,thereby increasing the clamp spacing between the at least two sidewallsat a location proximate to a distal end of the at least two sidewalls toat least the diameter of the first spinal rod, thereby permitting thefirst spinal rod to fit within the first spinal rod receiving passage.4. The spinal connecting device of claim 2, wherein the at least twosidewalls provisionally engage the first spinal rod and selectivelyretain the first spinal rod within the first spinal rod receivingpassage but allow the first spinal rod to slide along a longitudinalaxis of the first spinal rod within the first spinal rod receivingpassage upon application of an outside force.
 5. The spinal connectingdevice of claim 2, wherein the first spinal rod receiving passage has afirst longitudinally extending axis, and the second spinal rod receivingpassage has a second longitudinally extending axis, and the connectorbody is capable of rotating to a plurality of orientations relative tothe head assembly, at least one of the plurality of orientations beingwhere the first and second longitudinally extending axes aresubstantially parallel and at least one of the plurality of orientationsbeing where the first and second longitudinally extending axes aresubstantially perpendicular.
 6. The spinal connecting device of claim 2,wherein displacement of the head assembly towards the connector bodyurges the moveable wall from the first position to the second position.7. The spinal connecting device of claim 2, further comprising a singlelocking mechanism which, when actuated, fixedly secures the first spinalrod to the first rod clamp and fixedly secures the second spinal rod tothe second rod clamp.
 8. A connecting device for coupling a first spinalrod to a second spinal rod, comprising: a head assembly including afirst rod clamp, the first rod clamp including a first clamping assemblyto make a first provisional connection with the first spinal rod,wherein the first provisional connection engages the first spinal rodand applies sufficient frictional resistance to inhibit free movement ofthe first spinal rod relative to the first rod clamp but allow movementof the first spinal rod relative to the first rod clamp upon applicationof an outside force, and a connector body coupled to the head assembly,the connector body including a second rod clamp.
 9. The connectingdevice of claim 8, wherein the second rod clamp further comprises asecond clamping assembly to make a second provisional connection withthe second spinal rod, wherein the second provisional connection engagesthe second spinal rod and applies sufficient frictional resistance toinhibit free movement of the second spinal rod relative to the secondrod clamp but allow movement of the second spinal rod relative to thesecond rod clamp upon application of an outside force.
 10. Theconnecting device of claim 9, wherein the connector body is rotatablycoupled to the head assembly.
 11. The connecting device of claim 10,wherein the first clamping assembly engages the first spinal rod along afirst longitudinally extending rod axis, and the second clampingassembly engages the second spinal rod along a second longitudinallyextending rod axis, and the rotatable coupling facilitates relativedisplacement of the head assembly and the connector body to a pluralityof relative orientations, including a first relative orientation wherethe first and second longitudinally extending rod axes are parallel anda second relative orientation where the first and second longitudinallyextending rod axes are transverse.
 12. The connecting device of claim 8,wherein the second rod clamp further comprises a second clampingassembly that selectively engages the second spinal rod in response tomovement of at least a portion of the head assembly relative to theconnector body.
 13. The connecting device of claim 12, wherein theconnector body is rotatably coupled to the head assembly.
 14. Theconnecting device of claim 13, wherein the first clamping assemblyengages the first spinal rod along a first longitudinally extending rodaxis, and the second clamping assembly engages the second spinal rodalong a second longitudinally extending rod axis, and the rotatablecoupling facilitates relative displacement of the head assembly and theconnector body to a plurality of relative orientations, including afirst relative orientation where the first and second longitudinallyextending rod axes are parallel and a second relative orientation wherethe first and second longitudinally extending rod axes are transverse.15. A connecting device for coupling a first surgical rod to a secondsurgical rod, comprising: a first assembly including a first surgicalrod clamp, the first surgical rod clamp including a pair of flexiblejaws defining a first surgical rod receiving passage for accommodatingthe first surgical rod, wherein a distal portion of the flexible jaws isspaced apart a distance less than a diameter of the first surgical rodand retains the first surgical rod within the first surgical rodreceiving passage with sufficient frictional resistance to inhibit freemovement of the first spinal rod relative to the first rod clamp butallow movement of the first surgical rod relative to the first surgicalrod clamp upon application of an outside force, a second assemblyincluding a second surgical rod clamp, the second surgical rod clampincluding a fixed jaw and a moveable jaw, the fixed and moveable jawsdefining a second surgical rod receiving passage for accommodating thesecond surgical rod, wherein the moveable jaw in a first position isspaced apart from the fixed jaw a first distance that is less than adiameter of the second surgical rod and the moveable jaw in a secondposition is spaced apart from the fixed jaw a second distance that isequal or greater than the diameter of the second surgical rod.
 16. Theconnecting device of claim 15, wherein the first assembly is rotatablymounted on the second assembly.
 17. The connecting device of claim 15,wherein displacement of the first assembly towards the second assemblytranslates the moveable jaw to a locked position.
 18. The connectingdevice of claim 16, further comprising a locking mechanism which, whenactuated, fixedly secures the first surgical rod to the first assembly,fixedly secures the second surgical rod to the second assembly andimmobilizes the rotatable mount between the first assembly and thesecond assembly.
 19. The connecting device of claim 16, wherein thefirst surgical rod receiving passage includes a first longitudinalpassage axis and the second surgical rod receiving passage includes asecond longitudinal passage axis, and rotation of the first assemblyrelative to the second assembly orients the first longitudinal passageaxis at a plurality of orientations relative to the second longitudinalpassage axis, at least one of the plurality of orientations including afirst orientation where the first longitudinal passage axis is parallelto the second longitudinal passage axis and at least one of theplurality of orientations including a second orientation where the firstlongitudinal passage axis is transverse to the second longitudinalpassage axis.
 20. The connecting device of claim 15, further comprisinga spring connected to the moveable jaw and the fixed jaw, the springurging the moveable jaw towards the first position, wherein when thesecond surgical rod receiving passage accommodates the second surgicalrod, the spring applies sufficient force to the moveable jaw to create africtional resistance to inhibit free relative movement of the secondsurgical rod relative to the second surgical rod clamp but allowrelative movement of the second surgical rod relative to the secondsurgical rod clamp upon application of an outside force.